The overall objective of this research is to develop a general strategy for the assessment, prevention and treatment of debilitating joint contractures in spinal cord injury (SCI). Existing literature indicates that contractures in SCI do not respond to the same treatment modalities that may be effective in other paralyzing injuries. We believe that this is because SCI involves a combination of upper motor neuron(UMN) and lower motor neuron (LMN) damage coupled with widely varying voluntary muscle strength levels. The underlying hypothesis driving this project is that joint contractures in SCI have at least two distinct etiologies, and that further attempts at treatment will be unsuccessful without a better understanding of the factors influencing contracture development. Without a thorough, systematic analysis of joint contractures, their underlying biomechanics and their functional impact, we believe it will be extremely difficult to develop effective strategies to treat contractures and verify successful treatment outcomes. Therefore, our proposed project seeks to develop improved assessment techniques of the passive properties of the joints, perform these measures in a substantial cohort of SCI subjects, and use the information obtained to expose contracture etiology in SCI and to propose new treatment paradigms based on the understanding of this etiology. In this particular project, we will focus on contractures in the upper extremity, based on our previous work showing successful preliminary analysis of the passive properties of the hand and upper arm. The aims of this project are to develop a suite of tools for passive property assessment and to use this suite to evaluate both upper extremities in 60 chronic cervical-level SCI subjects. There are two anticipated outcomes of this study: 1) development of a clinical guide to passive property measurement that presents a streamlined set of data that maximizes the information obtained from simple clinical tests, and 2) development of a series of testable hypotheses regarding the etiology of joint contractures and possible prevention and treatment strategies. This will serve to guide future etiological and interventional research.